How do you take advantage of tax deductible donations?

I want to donate some money to wikipedia for their fund raiser. I was thinking maybe $25. I understand that donations are tax deductible, how do I actually make it known that I have donated? Probably a better question:
Because I am donating only 25 dollars, is this still tax deductible? Is there some reason that it would not be since I am still a minor?

When filing your income tax, you can either take a standard deduction or you can itemize. You can't do both, so if your itemized deductions aren't greater than the standard deduction (for a single filer for TY2006, that's $5,150), your question is moot.

As mentioned, you have to do the long form and itemize to deduct charitable contributions (it's deducted on Schedule A). Money donated to deductable charities is not taxed. The money donated is subtracted dollar for dollar from your Adjusted Gross Income when calculating your taxable income. Long story short, if you don't have a home mortgage, you come out way better taking the standard deduction.

Anf to add to that, the IRS has supposedly changed tax-deductable donations qualifications this year to thing ONLY with a receipt... like you can't deduct your weekly church donation with having a receipt or some such nonsence,

mr. b, i hope you realize that Wiki has spun into two - a non-profit and a for-profit entities? wiki is cool, but much better is the EFF (http://www.eff.org) and/or FSF (http://www.fsf.org)... i just popped $100 for the FSF, and at the same time, bought an autographed copy of rms' book (he signs it 'Happy Hacking!' which is how i signed all my books - i owe my second retirement to the GPL)...